Lapping machine



2 Sheets-Sheet 1 H. S. INDGE LAPPING MACHINE Filed Feb. 14, 1940 Nov. 11, 1941.

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Patented Nov. 11, 1941 UNITED STATES PATENT OFFICE LAPPING MACHINEHerbert s. Indge, Westboro, Mass assignor to Norton Company, Worcester,Mass., acorporation of Massachusetts Application February 14, 1940,Serial No. 318,739

3 Claims.

-A further object of the invention is to provide an improved drivingmechanism for the lower lapping element and work carrying cage. Anotherobject of the invention is to provide the improved lap and cage drivingmechanism with means to prevent dust and grit from getting into themechanism. A further object of the invention is to provide adequate dustand lubricant seals to prevent the admission of dust and grit to thedriving mechanism. A further object of the invention is to provide aself-contained lubricant system whereby the chamber surrounding the cagedriving mechanism is maintained full of lubricant under pressure. Otherobjects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elements,

and arrangements of parts, as will be exemplified in the structure to behereinafter described, and the scope of the application of which will beindicated in the following claims.

In the accompanying drawings, in which is shown one of the various.possible embodiments of the mechanical features of this invention,

Fig. 1 is a side elevation of the improved lapping machine, having partsbroken away to more clearly show the construction; and

Fig. 2 is -a fragmentary sectional view on an enlarged scale, takenapproximately'on the line 2-2 of Fig. 1. I

Referring more particularly to the embodiment illustrated, the lappingmachine may be constructed in its general aspects similar to the lappingmachine illustrated in my prior U. S. Patent No. 2,103,984 datedDecember 28, 1937. This machine, as illustrated, may comprise a base IIIwhich rotatably supports a lower lapping wheel The base III is providedwith an upwardly extending column |2 having an outwardly extendinghorizontal portion l3 which rotatably supports a vertical spindle M. Thespindle l4 carries a rotatable lapping wheel I5 which is connected tothe lower end of the rotatable spindle l4 by means of a supporting plateIt.

Power may be obtained from any suitable source, such as an overheaddrive shaft or an electric motor mounted on the machine. For

the sake of illustration, a belt drive has been shown comprising adriving belt 20 which serves to rotate a pulley 2|. The inner portion ofthe pulley 2| is formed as one part of a cone clutch. A slidably mountedcone clutch member 22 serves to mate with the clutch face within thepulley 2| to transmit a rotary motion to a rotatably mounted drive shaft23 which is journalled in .suitable bearings 24, 23, 26 and 21 'in thebase It. The clutch member 22 is slidably keyed to the shaft 23. Whenthe clutch member 22 is in the full line position (Fig. 1), no power istransmitted to the shaft 23. When it is desired to rotate the shaft 23,the cone clutch member 22 is moved toward the right (Fig. 1) intoengagement with the cone clutch member within the pulley 2| so as tocause rotation of the shaft 23.

In order that the clutch may be readily actuated from an operatingposition adjacent to the front of the machine, a pivotally mountedcontrol lever 23 is supported on a stud 23 on the base ID of themachine. The lower end of the lever 28 is connected by a stud 3|! with alink: 3| The link 3| is in turn connected by a stud 32 with the forwardend of a slidably mounted rod 33. The rod 33 is :lournalled in bearings34 and 35 which are fixedly mounted on the base ID of the machine. Therod 30 supports a vertically extending arm 36 which is yoke-shaped atits upper end and engages a groove 31 formed integral with the clutchmember 22. By movement of the control lever 28 in a counterclockwisedirection (Fig. l), the clutch member 22 may be thrown into engagementwith the clutch member formed within the pulley 2| to cause rotation ofthe shaft 23. An arrow point 31a projecting from the yoked portion ofthe arm 33 cooperates with a spring-pressed plunger 33 to maintain theclutch member 22 either in or out of engagement with the clutch memberformed within the pulley 2|. Similarly, when the lever 28 is moved in aclockwise direction into the position illustrated in Fig. 1, the clutchmember 22 is disengaged, thus stopping the rotation of The shaft 44 ispreferably a telescopic shaft and is they revolve.

on each of the studs 32 in such a position as toconnected at its end bya universal Joint 45 with the lower end of a rotatable shaft 40 whichthe column I2. The shaft 40 is provided with a multiple V-groove pulley50 which is connected by multiple V -belts 5i with a multiple V-groove3,202,? I I I the sears rotate. A cover-plate a encloses the 1 issupported in suitable bearings, not shown, in a bracket-43 whichisadjustably mounted on top of pulley slidably keyed to'rotate thevertical spindle I4. -When' the j clutchmember 22 is thrown intoengagement, a rotary motion is transmittedthroua'h the mechanism abovedescribed to rotate the pulley 50 which transmits a rotary motionthrough the V-belts II to the pulley 52 to rotate the vertical spindlel4 and. thereby rotate the upper lapping wheel It as desired.

The lower lapping wheel II is connected by a rotatable spider 55 to thupper end of a vertically arranged rotatable sleeve 56. The spider 55 iskeyed by means of a key 51 so as to rotate with the sleeve 56 in amanner to be hereinafter described. The sleeve 56 is journalled inbearshaft23 is rotated, a rotary motion is trans-,

mitted through the worm 52 and the worm gear to rotate the sleeve 56 andthereby rotate the spider 55 and the lower lapping wheel II.

The sleeve 56 also supports a gear 63 which meshes with a gear 64mounted adjacent to the lower end of a rotatable shaft 55. The shaft 55also carries a small gear or pinion ,66 at its lower end which mesheswith a gear 61 which is keyed to the lower end of a rotatable shaft 50.The shaft 68 is rotatably'supported in suitable bearings is and 10 whichare supported within the sleeve 56. The shaft 08 servesas a drivingmeans for a work. supporting cage I2 which is provided with a pluralityof work receiving apertures to simultaneouslysupport a plurality of workpieces 13 for a lapping operation between the opposed rotatable lappingwheels II and IS. A head 15 is keyed to the upper end of the shaft 63 soas to rotate therewith. The head I serves as a support for a'pluralityof studs I6, preferably three symmetrically arranged studs, only one ofwhich is illustrated in Fig. 2. These studs I6 are equally spaced fromeach other and are equidistant from the spindle 63 about which theyrevolve. Upon each one of the three studs 16 is rotatably mounted a gearTl. The gears 11 are arranged to continuously mesh with an internal ringgear. 18 which is fixedly mounted within the spider member 55. Agear 19is formed integral with or fixedly mounted relative to each of the gearsTI. The gears I9 are arranged to continuously mesh with a gear 80 whichis rotatably supported by an antifriction bearing 3| on the upper end ofthe shaft 63.

Three other studs 32 (only one of which has i been illustrated in Fig. 2are fixedly supported bythe head 15 equi-distant from each other andalso equi-distantfrom the shaft 63 about which A gear 33 is rotatablymounted be continuously in mesh with a pinion 34 which is either formedintegral with or fixedly mounted to rotate with the gear". A casing 35is formed as an integral part of j I the spider 55 and serves as acasing or container which surrounds the gear cage driving mechanism andserves as a lubricant containerin which upper open end of the casing II.A pair-of dust and lubricant packing rings "and 03 are provided toprevent lubricant leaking from the. casing 35 and also to-prevent dust.from-entering within said casing and thus coming in-Lcontsct with themoving parts. A cap." is fastened by screws 0| to the hub of each of thethree gears 03 so that it will rotate concentric therewith.

Each of'the caps00 serves as a support for a" I work cage supporting anddriving pin 32. The

driving pin 32 may be fixedly mounted relative to the cap 30 or may beadjusted relative thereto to varythe amount of motion transmittedthereby to the cage 12. Each of the caps 30 is provided with dust andlubricant packing rings 34. Also, packing rings 35 are interposedbetween the cover plate 36 and the cap 30, thus forming a double sealagainst. lubricant leakage from the casing 35 or grit passing throughinto the gear mechanism contained within the casing 35.

When the shaft 2: is rotated, the worm u will transmit a rotary motionthrough the worm gear 6| to rotate the sleeve 56 andspiderli .to

rotate th lower lapping wheel II. At the same time, the rotation of thesleeve 56 transmits a rotary motion through the gear 6.3, the gear 54,the gear 56, the gear 51, to rotate the shaft 53. Rotation of the shaft68 serves to rotate the head I5 which in turn transmits a rotary motionthrough the spaced cage driving pins 32 to rotate the cage I2 during alapping operation.

The gears 11 rolling in mesh with the stationary ring gear 18' transmita rotary motion through the gears 19 to the central gear and pinion 04which in turn transmits a rotary motion to the three gears 83 whichsimultaneously rotate the caps 30. The cage driving pins 92 are usuallyarranged ofi center'relative to the axis of rotation. of the caps so.Therefore, any rotary motion of the caps causes a gyrating' movement tobe imparted to the cage member 12 during the rotation thereof, thusproviding a combined rotary and gyrating movement of the work carryingcage 12 simultaneously to move a plurality of work pieces 13 through anirregular path between the operative faces of the lapping wheels II andI5 simultaneously to lap the opposed faces thereof. I 4

In order to attainone object of the invention, it is desirable toprovide a lubricant system whereby the chamber within the casing 35 mayat all times be maintained filled with lubricant under pressure so as toprevent the formation of a partial vacuum with the resultant sucking inof grit and other foreign material which would rapidly wear the cagedriving parts and bearings therefor. contained lubricant system is.provided comprising a lubricant reservoir 99 formed within the base I0of th machine. A lubricant pump I00 is formed integral with a coverplate IOI for convenience of assembly. The lubricant pump I00 comprisesa reciprocable plunger I02 which supports a roller I03 on a stud I04which is carried by a bracket I05 fixedly mounted on the end of theplunger I02. An eccentric I00 is mounted on the drive shaft 23 andserves through the roller I03 to transmit a reciprocatory movementto thepump plunger I02 when the shaft 23 J is rotated. A compression springI01 serves at "alljtimes to maintain the roller I 03 in operative'engagement with the cam or ec-' centric I05.

Lubricantunderpressure is pumped from the In the preferred form, aselfreservoir 99 through a strainer I08, through a pipe I09, through aball check valve H0, into a pump chamber I I I. When the plunger I02reciprocates, fluid is forced under pressure through a bined rotary andgyrating movement is entirely.

surrounded by lubricant under pressure so that all of the moving partsare adequately lubricated. It is desirable to maintain a sufiicientpressure on the lubricant within the chamber H6 to prevent any airpockets or creation of a partial vacuum, so as to prevent dust orforeign matter from working into the chamber H8 by passing the oil andgrit seals above described.

In order to maintain a uniform pressure on the lubricant within thechamber H6, an ad- :lustable ball check valve H1 is provided. Lubricantunder pressure within the chamber H6 fills a vertically extendingpassage H8 to the ball check valve H1. The ball check valve I I1 ismaintained in a closed position by means of a spring H9, the tension ofwhich may be adiusted by means of a screw I20. By varying the tension ofthe spring I I9, the pressure of the lubricant within the chamber I I 6may be varied as desired. When the pump I forces lubricant into thechamber I It to the extent that the pressure rises above the pressureset for the ball check valve I II, the ball I I1 is forced downwardly toallow excess lubricant under pressure to pass through a passage I2Iformed in the casing 85.

Lubricant passing through the passage I2I may pass downwardly through anenlargedbore or chamber I22 within the bracket 00 and drains through apassage I23 into the reservoir, within the base I-0. By adjustment ofthe screw I20, the pressure of the lubricant within the chamber H0 maybe readily varied as desired, so that it is sufficient to maintain afull chamber of lubricant and sufllcient to prevent creation of apartial vacuum and thus stop leakage of grit or foreign matter by thelubricant and dust seal rings 81 and 88. In case the passage H8 shouldbecome clogged, a second ball check valve I25 is provided which isconnected by a short passage with the lower portion of the chamber H8. Ascrew I26 is provided for adjusting the compression of the spring I21.This ball check valve I2! is adjusted to a slightly higher pressure thanthe ball check valve I ll so that normally the ball check valve II'Ifunctions to release excess lubricant under pressure. In case of a.stoppage in the passage H8 and a resultant increase in lubricantpressure within the chamber H6, the bail check valve I25 will open andallow lubricant from the lower portion of the chamber I It to passoutwardly through the ball check valve H1 and thereby retum'to thereservoir 89.

The operation of the improved lapping machine will be readily apparentfrom the foregoing disclosure. 'The reservoir 09 within. the base I0 isfilled with lubricant sufficient to maintain a level substantially up tothe center of the drive shaft 23, thus providing adequate lubricationfor the gear mechanism within the base.

When a lapping operation is started and the control lever is shifted toengage the clutch member 22 to start a rotary motion of the shaft 23,the rotation of the eccentric I06 starts reciprocation of the pumpplunger I02 to force lubricant through the central aperture H5 in theshaft 68 to maintain a desired and predetermined lubricant underpressure filling the entire chamber H0 within the casing 85 toadequately lubricate the gears and bearing parts, maintaining a fullchamber and thus preventing creation of a partial vacuum and eliminatingthe danger of dust, grit or foreign material passing the lubricant anddust seals, as above enumerated.

It will thus be seen that there has been pro- ,vided by this inventionapparatus in which the various objects hereinabove set forth togetherwith many thoroughly practical advantages are successfully achieved. Asmany possible embodiments may be made of the above invention and as manychanges may be made in the embodiment above set forth, it is to beunderstood that all matter hereinbefore set forth or shown in theaccompanying drawings is to be interpreted as illustrative and not in alimiting sense.

I claim:

, 1. In a lapping machine having a base, a work carrying cage, meansincluding a gear mechanism to rotate and gyrate said cage, a rotatablecasing surrounding said mechanism, a lubricant pump within the base,lubricant connections between said pump and said casing, means toactuate said pump to maintain lubricant under pressure Within saidcasing, and means including an adjustable relief valve in said casingwhereby the lubricant pressure may be varied as desired.

2. In a lapping machine having a base, a rotatable lapping wheel, a workcarrying cage, a hollow casing to support said wheel, means including agear mechanism within said casing to rotate and gyrate said cage, meansincluding a rotatable drive shaft in the base which is operativelyconnected to rotate said lapping wheel and to actuate said gearmechanism, and a lubricant system within said base including a lubricantreservoir, a lubricant pump, lubricant connections between said pump andeasing, driving connections between said shaft and pump, and anadjustable relief valve in said casing whereby said casing may bemaintained filled with lubricant under a desired and predeterminedpressure.

3. In a lapping machine having a base, arotatable lapping wheel, a workcarrying cage, 9.

v hollow casing to support said wheel, means including a gear mechanismwithin said casing to rotate and gyrate said cage, means including arotatable drive shaft in the base which is operatively connected torotate said lapping wheel and to actuate said gear mechanism, and alubricant system within said base including a lubricant reservoir, alubricant pump, lubricant connections between said pump and said casing,an adjustable pressure relief valve in said casing, and an eccentric onsaid drive shaft to actuate said pump whereby lubricant under thedesired and predetermined pressure may be maintained in said casing.

HERBERT S. INDGE..

